Apparatus for controlling boiler soot blowers and the like



March 11, `1958 F. L. MURRAY, JR

APPARATUS FOR coNTRoLLING BOILER soo: BLowERs AND THE LIKE Filed July v. 1955 United States Patent O Y RegisPaperCompany, New York, N. Y., a corporation ktofN ew York .ApplicationJuly `7, 1955,`Sexial1No. 520,532

3 Claims. (Chili- 316) ,This inventionrelates to apparatusfor automatically controlling soot 'blowers` suchias used in water tubeboilers periodically, to provide air puls for blowing soot and ash from the boiler tubes, andmorerspecically the inventiony relates to equipment for controlling,` theI timing, of the cyclesA of operation of4 groups of such: blow:- ers. The invention is adapted for use in connection withwater tube, boilersgenerally, and is particularly` well radapted for` usefin connection wi-th. black liquor;recovery boilers, lsuch. as` are 'now used inthe paper industry.

Y'In-such. boilers, it isnecessary to` provide somefmeth- Qd. fandimeans kfor, removing. soot and ash' accumulations -from the boiler. tubes to assurey continuous and t efcient operation. It is-acommon lpractce to accomplish this bfyproviding means known as soottblower headsatanu merous places around and Within the boiler for injecting pulls` of ainor steam.` Ini-,a t-ypicalinstallation, asimany as. twentyffour of, such..soot blowerl head assemblies are provided, located'at `spaced pointslwith perforated iiuid ,discharge pipes projecting` into the. space'between thefboil- 'er tu'b'eseach of the nozzles .being rotatable; aboutits axis so astodirect successive. puffs of. air or steam `in various different directions.

Since theU continuous. operation., of such 1soot blowers would interfere with the proper operation of ,the boiler and'requirethe use of `excessive and` expensive quan,i

titiessoff steam orairounder pressure, yit iscommonyprac- `tice to operatesuch blowers periodically and to-cause them to be actuatedxinv groups: withapredetermined sequence and with. each group divided into subegmups. But the necessary control equipment for, the numerous groups andsub-groups becomes relatively complicated with numerous valves and other parts which may easily become inoperative. Also, whilesuch heretofore-known equipment has provided for a complete cycle of operation of` all the groupsrand sub-groups in properfsuccesf sion,A yetat theyend .of,.such cycle, such equipmenthas to` b'e manually resetloristarted ata later timev to cause it toi operate through` another cycle. These .factors have resulted` in excessive costsdue: to thev almost constant requirements for maintaining and attending such equipment. The priorvknown apparatus for the purposehas also required-meuse` of an ,expensive control panel posi't'ionedl atv a rplace convenient .to an attendant and;yet oftenquite-.remote from theboilerso that in the presence oijcorrosive atmospheric conditions in the plant, `considerable expense is involvedfor maintaining, and replacing, t from time. toqtime, long lengths of 4v,numerous pressurecontrol tubes..

` 'The cpresentinvention. provides` a substantially simpl'iied arrangement of apparatus, which `is certainftand dependable in operationfandtrequires little; expense ifor maintenance. Also,.with thepresent invention, thezequip ment is entirely'automaticin. thatit will operate:continously through successive cycles without requiring an attendanttmanually torinitiateveachr cycle.r Further! more, no remotely located ,control panelboardis-required:

Various-further and-more specicsobjects, .features and advantages of the invention will! appear vfrom, the de tailed descriptiongiven below,.itakenxin connection with the accompanying drawings which `form-a partof this .specilc'atitm` and illustrate. ,merelyl :by way of, example atipreferred formxof the invention. .The .invention con sists in. such novel features, arrangements and combina# tions ofipartsvasimay beshownand describeduherein.

Inthedrawings:

Fig; l is -ra schematic .diagram of? a. preferred embodiment `of the zcontrol equipment` of the' present' invention; and

Fig.y 2 isz/a somewhat.schematicrdiagramrof certain of the principalV operating parts of alknown form of dis- Atrbutornvalve 'mechanism used iin the; system of 'Figi Referring now to Fig. 1 in further detail, one of the so-callednsoot blower; headna'ssem-blies, which may be of ra wellsknown constructiomis somewhat schematicallyilndicatedat 10. Suchvrassemblies include aperforated pipei-asoatl. `L1, which projects through the `wall of the boiler intoxthezspaces between banks of boiler tubes. The perforated pipes as'at 11-are arranged 'to be rotated .about .theiriaxesy stepfby step, so that each timea pul ofv s-teanfraorr` ain'is projectedfrom'the perforations, the puiwilltbe directedA at` a different angle with respect `eto-the'taxisrato'insurebiowirfg the soot andash from all parts. of;..the=boilertubes.. ySuch step-bystep rotation of the tube: f11,4 may Ibe accomplished: by ratchet means of knownxformsuchasschematically indicated at *12, suit- -ablyzactuated by` acyilnder and pistondevice at'-13.

`Sincelthe variouscontrol devicesfor` periodically caus- `ingaadmission of the pressureto the'soot' blowerheads involve" the use ofv numerous valves and other `mechanisms', it is desirablethat these parts be made relatively smalband. as'inexpensive'as possible, and for that reason it would be practically prohibitive to make such control kvalves,andi-the conduits connecting same large enough to conductftlre` large volumes of blowingair or'steam therethrough". Accordingly, as is common practice, each soot. blower head assembly preferably `includes suitable valve-:means located as at 14, which may -be` for eX- ample :a piston ityp'e valveactuatable by lthe` control 'sys'- item hereinafterdescribed, to' admit periodicallyth'e'large Volumes ,of.'airunder'pressurethrough' a main "line15 comngrrom'azcompressor `and storage tank asl at 16', 17.

The r`overall.` purpose of the" control equipment now about' tobe described is toV provideat propenintervals 'to-eachysoot `blower head, air orsteam under/pressure fthrough-a pipe. as at 18ifor simultaneously actuating the ,sootblowenhead valve 14, aswell as to-actuate Athe pistonv in `the cylinder. 13 for moving theratChet'IZto rotate theblowing tube one step yabout its axis atth'e beginningof each puit.

The apparatus assschematically shown inthe upper portion'of Fig. 1 comprises equipment for controlling one'fsub-group ofthe soot blower heads. That is, for example, ,asubagroup actuating a total of eleven blower heads, each :receiving air pressure from branches 'of pipe 15as indicated '.by .therarrows 20.- The'controlpipe` connections;` for these` blower head assembliesrespectively are indicated .by .the arrowsZI. `It will betund'erstood thatffeach sub-'group may: actuate a lgreater number, but usually-a smaller number of blower heads. Also, inthe lexample indicated, the group is dividedA into sub-subgroups, eachhaving kcontrol. pipe connections as atZZ-Z'S, inclusive.

Certainl of `the devices schematically indicated along thealowerhportion of Fig. 1, as hereinafter explained, arecommon toi'allof three maingroups :of .blower heads.

Thecontrolarrangemeut and equipmentrxandfits operation, as shownrinthe upper partof Eig. 1, fwilllnowbe explained.

seamen Pressure from the compressor and tank 16, 17 enters a diaphragm operated control valve 26 which will be considered as being held in open position at the start by pressure admitted through connection 27 to the diaphragm of the valve. The pressure in the tank 17, for example, may be normally maintained between 200 and 300 p. s. i. and such pressure subsequent to the control valve 26 is conducted through a connection 28 and through another diaphragm operated valve 29 into what will be termed a ratchet operated distributor valve 30 which acts at proper intervals sequentially to admit pressure to the control connections 22-25, inclusive. The device 30 may be of well-known type, an example of which is commercially available under the name AMC Distributor, as put out by Diamond Power Specialty Corp. of Lancaster, Ohio, the principal operating parts of which are schematically shown and hereinafter described in connection with Fig. 2, although it will be understood that other forms of distributor valve means might be provided for the purpose.

The distributor valve means 30 may be actuated by a cylinder and piston device 31 which receives air pressure at intervals through connection 32 which in turn is under the control of a solenoid operated valve 33. The solenoid of this valve may be energized at predetermined intervals by using any of the numerous wellknown types of timing switches commonly available, preferably of a form lhaving all of its mechanism enclosed and protected against deterioration, so as to insure reliable operation. For example, a tiltable mercury switch as at 34 may be provided for the purpose, having suitable pivotal supporting means as at 3S adapted to be tilted at intervals by a rotating cam 36 driven by a motor 37. The speed of the motor is preferably adjustable as by a rheostat 38 in order to permit adjustment of the intervals of operation of the switch. For example, in a typical instance, this switch is arranged to close a circuit to the solenoid for periods of about 1% seconds duration, which periods may, for example, be spaced apart by 7 to 8 seconds.

In lieu of the mercury switch arrangement above described, other well-known types of electrical timing devices might, of course, be used if constructed for highly reliable operation over long periods of time without attention, for example a so-called scanning-oscillator type of unit may be used as put out by Minneapolis- Honeywell Regulator Company, and same have been found highly satisfactory and reliable for the purpose.

The pressure supply to the solenoid-operated valve 33 is derived from a connection 40 communicating with the conduit 28, the pressure supply passing through a reducing valve 41, thence through a connection 42 and through a pressure-actuated valve 43 and a connection 44 into the solenoid-operated valve 33. The pressurereducing valve 41 is adapted, for example, to reduce the pressure running to the valves 43 and 33 from the range of 200-300 p. s. i. down to say, 110 p. s. i., so that lower pressure operating valves at lesser maintenance costs may be used subsequent to such reducing valve.

During the normal operation of the equipment, at the outset of each pul of air through the soot blower heads, the pressure available from the tank 17 will tend to be considerably greater than after a succession of pulses has occurred. For example, the pressure may fall from about 300 p. s. i. down to the neighborhood of 200 p. s. i. after. a series of pulls, and it is accordingly desirable to stop the puffs at that point until full, normal air pressure can be restored, since it would be a waste of air pressure to provide same at the blower heads at a low and ineffective pressure. To accomplish this purpose, the pressure operated valve 43 is provided and is arranged tobe actuated by a spring to closed position, when the pressure in pipe 2S falls to a predetermined level, such as 200 p. s. i. The valve 43 is normally held open by a pressure diaphragm subjected to pressure through a connection 45 which communicates with pipe 28. The valve 43 should be one of the well-known suitable types which will be actuated to closed position at the predetermined lower pressure limit, say, of 225 p. s. i., but the construction being such that the valve will not open again -until the pressure is restored to normal, for example 300 p. s. i.

The distributor valve 3d of types normally available is so constructed, that its ratchet stepping mechanism may not be readily actuatable to move a valve-piece when subjected to heavy pressure. For this reason, the pressure diaphragm operated valve 29 is provided in the line 23 in advance of the distributor valve 30. The valve 29 is normally closed, but when a pressure impulse is provided in connection 32, the same impulse transmitted through connection 32a will actuate the diaphragm of valve 29 to open this valve just as the ratchet stepping mechanism of valve 3i) is actuated in one direction. Then when the pressure impulse is cut 0E, valve 29 will close, pressure in connection 46 Will subside, and the ratchet mechanism at 31 will be free to actuate inthe other direction.

Thus, with the arrangement above described, successive short puffs of pressure Will be supplied to the actuating piston 31 of the valve 30 through connection 32, such puffs being occasionally interrupted by the action of the valve 43 when the pressure supply falls too low and until pressure is restored to normal. Actuation of the ratchet-like mechanism associated with valve 30 will cause the valve-piece to be turned to successive positions for distributing the pressure supply coming in through connection 46 in succession to the connections 22 to 25, respectively, runmng to the sub-sub-groups of soot blowers.

When the valve-piece in the valve 30 has stepped around to the last step of its cycle of revolution, pressure will be discharged through a connection 50 to actuate the diaphragm of a diaphragm-controlled valve 51. This valve is thereby opened to admit pressure, say at about p. s. i. through a connection 52 running from connection 42 to the valve 51, the pressure at the outlet side of this valve being conveyed through a connection 53 to an actuating cylinder and piston means at 54, for another ratchet-operated distributor valve 55, which may be of a construction similar to the valve arrangement 30, 31 above referred to. The valve 55 is for the purpose of distributing pressure in succession through connections 27, 27a and 27h for respectively actuating valves 26, 26a and 26h, which act to put in operation when opened, the control equipment for each of three main groups of soot blowers. For the example of the invention here being described, it will be understood that the valves 26a and 26b are each connected to control systems like that schematically shown along the upper part of Fig. l, but for controlling respectively each of the three main groups of soot blower heads. When the cycle of actuation of each of such controls is completed, its distributor valve, in its last position of rotation, will apply pressure through connections 50, 50a or 50b, for actuating, as the case may be, the corresponding valve 51, 51a or 51b, these valves in turn admitting pressure to actuate step-by-step the valve 55 and thereby causing the valves 26, 26a, 26b in turn to be opened to initiate the operation of each of the control arrangements for the three main groups of blowers.

Pressure is admitted to valve 55 in the following way. A connection 60 communicating with the main tank 17 runs to a reducing valve 61, thence through a connection 62 to a three-way valve 63 which is diaphragm-operated, and thence through a connection 64 to the distributor valve 55. Then when pressure is supplied through connection 53 and thence through connection 65 to actuate the diaphragm of valve 63, this valve will momentarily cut ot the pressure through connection 64 and instead discharge pressurev from connection 62 to an exhausti E' A i outlet` 6 6. Meanwhile, ttlief -pres'sureiir l'connection .5,3

will actuatejgthevalve `SSone; step to; transfer the-control 'from Vthe 'first main group of control apparatus, above `in1connections=53 and 65 will subside, allowingthree-way valve 63` to move' back to normal position, shuttingv1 ott exhaust 6 6v and l placing the connections, in condition ffor the' next operation of distributor valve 55.

In order' thatthe lpressures on the downstreamsides ol' the various lcontrol valves `above described, willpromptly sub'sidewhen such ,valvesare closed, Iit will be understood that suchvalvesmay be .of 4the.sfo-called', ,selfgbleeding type on the downstream side.

The roperation of one particular type of4 distributor valve,such as the valve 30r will Znow `be `summarized-in connection with the schematic `diag`ram. of.;l*`ig. 2. The essential parts of this mechanism may comprise cylinder and piston means 31, `the piston havinga` restoring spring 31a and the piston.v rod` beingconnectedto a crossbar as at 70 which, upon actuation of the piston, is pushed `in atrforward direction along the teeth of a ratchetv wheel ,71 and* along the periphery of a disc 72 mounted" on a common shaft 73. When the pressure in connection 32 is released, the spring 31a will retract the bar 70 and cause pawl 74 thereon to engage one of the teeth on ratchet wheel 71 and at the same time a pawl 75 on the other end of cross-bar 70 may engage one of the pins 76 on a wheel 77. The pawls 74 and 75, as indicated, may be accompanied by springs normally to hold them in downwardly projecting position. The wheel 77 is rotatably mounted on another shaft 78 coaxial with shaft 73. Shaft 78 has secured thereon to rotate therewith a disc-like valve-piece 79 having an orice 80. The disc 79 rotates in a space formed between two stationary valve housing members 81 and 82. The member 8l is formed with a plurality of radially extending port-like cavities as at 83, communicating respectively with the several pressure lines such as at 22-25 and 50, as indicated in Fig. l. The disc-like valve-piece 79 rotates step by step, the port or opening 80 will come into register with one or another of the port cavities as at 83, and thus distribute t-he control pressure successively to the several sub-groups of soot blowers. The valve housing portion or member 82 is provided with an inlet connection with the line 46.

The pins 76 on wheel 77 are so mounted that they may be pulled out to extended positions when desired, as is shown in the case of pin 76a. One of such pins is provided corresponding to each of the valve outlet connections, and in case some of these outlet connections are not being used, then the corresponding pin is pulled out at at 76a.

It will be noted that the disc 72 has a notch at 84, which, once during each revolution, will come into a position under the bar 70 and allow the bar to drop down slightly. Thus, when the bar 70 is held up on the periphery of the disc 72 in the position shown in Fig. 2, the pawl 7S, when retracted, will be free to pass the normally positioned pins 76, but when one of the extended pins, as at 76a, comes opposite the pawl 75, then the pawl will angularly move the wheel 77 one step in the direction shown by the arrow thereon.

Assuming an air pressure impulse is applied to connection 32 and at the same time to connection 46, the bar 70 will be moved forwardly without moving the parts 71, 72 or 77, and meanwhile air pressure through connection 46 and valve aperture 80 will be transmitted to one or another of the distributing connections 22--25 or 50, which is then located with its port opposite opening 80. Then when the pressure impulse through connections 32 Iand 46 is terminated, the spring 31a will retract the bar 70 and cause the ratchet wheel 71 to be rotated in the direction indicated by thearrow thereon by an amount correspondiir'g tofone tooth. `Andifratthatniort-telit 'one'.fthe extendedp'i'uspas'A at 76a,"isin position: to` be engaged* by thepawl 75, thenthe valve=piece 79 will bek rotated"o'ne step'.` Then when the nextpressure impulse occurs;jthe

ratchet wheel 71 has'for exampletwenty-one teeth, then twenty-'onepuisof'air will be appliedto each of the subgroups of sooty blowers kbefore the valve meansis, moved toA thenext step corresponding to the next sub-group of blowers. Further, it will benoted, that in casesfwhere one offv the' extended pins, as at, 76a, which corresponds t'o-an'unusedi outlet port,lco'mes'into' position, such outlet port will'receive but one p ut before `the valve'4V is stepped toA the next position; v

It isi-notedthat thefratchetiwheel 71 may appropriately 'have'the-same number of teeth as theratchet wheelssc'hematically indicated at 12on the soot blowers. This. will insure that `for each revolution of the ratchet wheel"71 and disc 72, the soot blower pipes, as at 11, will be rotated through one complete revolution.

The ratchet-operated distributor valve indicated at 55 in Fig. l, may be like the one schematically shown in Fig. 2, except as will now be explained. The valve 55 is shown in Fig. 1 as having three outlet connections 27, 27a and 27b, but if, say, the valve has twelve angularly spaced outlet ports, each of the three outlet connections, respectively, would have parallel connections to every third outlet port and twelve of the corresponding pins, all in extended position (as pin 76a) would be provided, so that upon each pressure impulse the valve would be turned one step.

Although a preferred embodiment of the invention is herein disclosed for purposes of explanation, various modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

l. Apparatus for controlling the operation of pluralities of main groups and sub-groups of boiler soot blowers of the type having a fluid pressure controlled inlet valve for admitting puits of blowing fluid thereto and having uid pressure operated means for turning the blower toward various directions, such control apparatus comprising in combination a first distributor valve common to the control apparatus for all the main groups and associated with fluid pressure operating means and connections including valves for admitting pressure to the control apparatus for each main group of blowers successively, other pressure control distributor valves for each of the main groups respectively and means associated with said other distributor valves including connections and pressure operated means therefor, for distributing pressure control puits to the soot blowers of the sub-groups in succession for actuating the inlet valves and turning means thereof, timing devices associated with the operating means for each of said other distributor valves for causing actuation of the latter at predetermined timed intervals, said other distributor valves also each having connections and associated valve means for causing actuation of said first-named distributor valve following the distribution of pressure control puffs to each of said sub-groups, whereby said first-named distributor valve then admits pressure to the control apparatus for the next main group.

2. Apparatus for controlling the operation of pluralities of main group-s and sub-groups of boiler soot blowers, comprising in combination a first distributor valve com mon to the control apparatus ttor yall the main groups and Aassociated with fluid pressure operating means and connections including valves for admitting pressure to the Acontrol apparatus for each main group of blowers successively, other pressure control distributor valves for each ing the distribution of pressure control puffs to each of said sub-groups whereby said first-named distributor valve then admits pressure to the control apparatus for the next main group. v

3. Apparatus for controlling the operation of pluralities of main groups and subfgroups of boiler soot blowers, comprising in combination a rst distributor valve common to the control apparatus for all the main groups and associated with fluid pressure operating means and connections inclu-ding valves for admitting pressure to the control apparatus for each main group of blowers successively, other pressure control distributor valves for each of the vmain groups respectively and means associated with said other distributor valves including connections and ,pressure operated mean-s therefor, for distributing pressure control puffs to the soot blowers of the sub-groups in succession for actuating same, timing devices associated with the operating means for each of said other distributorrvalves for causing actuation of the latter at predetermined timed intervals, the operating means for said other `distributors respectively also having associated therewith valves actuatable in response to abnormal reduction oE `the supply pressure to the soot blowers to interrupt the operation of said other distributor valves until the normal soot blower pressure is restored, said other distributor valves also each having connections and associated valve means for causing actuation of said first-named distributor valve following the distribution of pressure control puffs to each of said sub-groups, whereby said first-named distributor valve then admits pressure to the control apparatus for the next main group.

References Cited in the tile of this patent UNITED STATES PATENTS 1,680,125 Bowers Aug. 7, 1928 2,049,421 Brelsford et al. Aug. 4, 1936 2,327,524 Hibner et al Aug. 24, 1943 

